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Numéro de publicationUS5991287 A
Type de publicationOctroi
Numéro de demandeUS 08/775,122
Date de publication23 nov. 1999
Date de dépôt30 déc. 1996
Date de priorité30 déc. 1996
État de paiement des fraisPayé
Autre référence de publicationCA2221231A1, CA2221231C, EP0851631A2, EP0851631A3, EP0851631B1
Numéro de publication08775122, 775122, US 5991287 A, US 5991287A, US-A-5991287, US5991287 A, US5991287A
InventeursWilhelmus J. M. Diepstraten, Leo Monteban
Cessionnaire d'origineLucent Technologies, Inc.
Exporter la citationBiBTeX, EndNote, RefMan
Liens externes: USPTO, Cession USPTO, Espacenet
System and method for providing seamless handover in a wireless computer network
US 5991287 A
Résumé
For use with a wireless computer network having a plurality of access points, a mobile station adapted for communicating with the network via a current access point and having a scanning circuit for locating a new access point, the scanning circuit requiring a scanning period of time to locate the new access point, a method of operation of the mobile station and a wireless computer network infrastructure. The mobile station comprises: (1) a detection circuit that generates a ready-to-scan signal indicating that the mobile station is about to activate the scanning circuit and (2) a suspension circuit, coupled to the detection circuit, that receives the ready-to-scan signal and generates, in response thereto, a data suspend signal for transmission to the current access point, the data suspend signal causing the current access point to suspend transmission of data to the mobile station, thereby preventing loss of the data during the scanning period.
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Revendications(20)
What is claimed is:
1. For use with a wireless computer network having a plurality of access points, a mobile station adapted to communicate with said network via a current access point and having a scanning circuit for locating a new access point, said scanning circuit requiring a scanning period of time to locate said new access point, said mobile station comprising:
a detection circuit that generates a ready-to-scan signal indicating that said mobile station is about to activate said scanning circuit; and
a suspension circuit, coupled to said detection circuit, that receives said ready-to-scan signal and generates, in response thereto, a data suspend signal for transmission to said current access point, said data suspend signal causing said current access point to suspend transmission of data to said mobile station, thereby preventing loss of said data during said scanning period.
2. The mobile station as recited in claim 1 wherein said current access point buffers said data during said scanning period.
3. The mobile station as recited in claim 1 wherein said data suspend signal is a power save mode enable signal conforming to an IEEE 802.11 protocol.
4. The mobile station as recited in claim 1 wherein said detection circuit is further capable of generating a scan-complete signal, said suspension circuit generating, in response thereto, a data resume signal for transmission to said current access point, said data resume signal causing said current access point to resume transmission of data to said mobile station.
5. The mobile station as recited in claim 1 wherein said suspension circuit is further capable of polling said current access point to cause said current access point to transmit said data to said mobile station.
6. The mobile station as recited in claim 1 wherein said suspension circuit is further capable of transmitting a data resume signal, said data resume signal being a power save mode disable signal and a polling signal conforming to an IEEE 802.11 protocol.
7. The mobile station as recited in claim 1 wherein said scanning circuit is a frequency scanning circuit.
8. For use with a wireless computer network having a plurality of access points and a mobile station adapted to communicate with said network via a current access point and having a scanning circuit for locating a new access point, said scanning circuit requiring a scanning period of time to locate said new access point, a method of preventing data loss during said scanning period, comprising the steps of:
generating a ready-to-scan signal, said ready-to-scan signal indicating that said mobile station is about to activate said scanning circuit; and
generating, in response to said read-to-scan signal, a data suspend signal for transmission to said current access point, said data suspend signal causing said current access point to suspend transmission of data to said mobile station, thereby preventing loss of said data during said scanning period.
9. The method as recited in claim 8 further comprising the step of buffering said data in said current access point during said scanning period.
10. The method as recited in claim 8 wherein said data suspend signal is a power save mode enable signal conforming to an IEEE 802.11 protocol.
11. The method as recited in claim 8 further comprising the steps of:
generating a scan-complete signal indicating that said scanning period has terminated; and
generating, in response to said scan-complete signal, a data resume signal for transmission to said current access point, said data resume signal causing said current access point to resume transmission of data to said mobile station.
12. The method as recited in claim 8 further comprising the step of polling said current access point to cause said current access point to transmit said data to said mobile station.
13. The method as recited in claim 8 further comprising the step of transmitting a data resume signal, said data resume signal being a power save mode disable signal and a polling signal conforming to an IEEE 802.11 protocol.
14. The method as recited in claim 8 wherein said scanning circuit is a frequency scanning circuit.
15. A wireless computer network infrastructure, comprising:
at least one central server having a plurality of access points operating at different frequencies; and
a plurality of mobile stations adapted for communicating with said network via a corresponding plurality of current access points, each of said plurality of mobile stations having data processing and storage circuitry and a frequency scanning circuit for locating a new access point, said scanning circuit requiring a scanning period of time to locate said new access point, said each of said plurality of mobile stations further including:
a detection circuit that generates a ready-to-scan signal indicating that said mobile station is about to activate said frequency scanning circuit, and
a suspension circuit, coupled to said detection circuit, that receives said ready-to-scan signal and generates, in response thereto, a data suspend signal for transmission to said current access point, said data suspend signal causing said current access point to suspend transmission of data to said mobile station, thereby preventing loss of said data during said scanning period.
16. The infrastructure as recited in claim 15 wherein said current access point buffers said data during said scanning period.
17. The infrastructure as recited in claim 15 wherein said data suspend signal is a power save mode enable signal conforming to an IEEE 802.11 protocol.
18. The infrastructure as recited in claim 15 wherein said detection circuit is further capable of generating a scan-complete signal, said suspension circuit generating, in response thereto, a data resume signal for transmission to said current access point, said data resume signal causing said current access point to resume transmission of data to said mobile station.
19. The infrastructure as recited in claim 15 wherein said suspension circuit is further capable of polling said current access point to cause said current access point to transmit said data to said mobile station.
20. The infrastructure as recited in claim 15 wherein said suspension circuit is further capable of transmitting a data resume signal, said data resume signal being a power save mode disable signal and a polling signal conforming to an IEEE 802.11 protocol.
Description
TECHNICAL FIELD OF THE INVENTION

The present invention is directed, in general, to a wireless computer network and, more specifically, to a system and method for providing seamless handover in a wireless computer network.

BACKGROUND OF THE INVENTION

Computer systems configured as local area networks have been common for nearly two decades and are popular in a wide variety of business and educational applications. The most common LANs comprise a number of processing devices and a server that are coupled together by a hard-wired connection. Since about 1990, however, wireless local area networks (LANs) have become more common in the marketplace. Although the concept behind wireless LANS had been described a decade earlier, interest in LAN networks was limited until the release of the 2.4 GHz unlicensed band for industrial, scientific and medical (ISM) applications. Wireless LAN products most often employ either direct sequence spread spectrum (DSSS) or frequency hopping spread spectrum (FHSS) techniques to communicate between roaming mobile stations and network access points.

In a typical wireless computer network environment, the "backbone" of the LAN is a central server that communicates with a number of network access points through a hard-wired connection. Each access point (AP) includes a transceiver for communicating with at least one roaming mobile station (MS). The mobile station may be a point-of-sale terminal (i.e., an electronic cash register), a bar code reader or other scanner device, or a notepad, desktop or laptop computer. Each MS establishes a communication link with an AP by scanning the ISM band to find an available AP. Once a reliable link is established, the MS interacts with other mobile stations and/or the server. This allows the user of the MS to move freely in the office, factory, hospital or other facility where the wireless LAN is based, without being limited by the length of a hard-wired connection to the LAN.

Eventually, as a roaming mobile station moves in a multi-channel wireless LAN environment, the mobile station will move out of the range of its current access point. When this occurs, a "handover" takes place that breaks down the communication link between the mobile station and the current access point and establishes a new communication link between the mobile station and a new access point. The mobile station initiates this process when it detects that the link quality with the current access point has degraded below a specified threshold. The mobile station then begins looking for another access point, probably in a different frequency channel.

During this frequency scanning period, however, the mobile station will be tuned to a different frequency channel than is used by the current access point. Thus, any messages that are received by the current access point and destined for the mobile station that is scanning will be lost if transmitted during the scanning period. Present IEEE communication standards do not define protocols which allow the mobile station to inform the current access point that the mobile station is scanning and to request that the mobile station buffer any received messages for a short period of time.

Accordingly, there is needed in the art systems and methods that prevent loss of data during the scanning period of a roaming mobile station. There is a further need for systems and methods that prevent loss of data during the scanning period of a mobile station without modification of existing access points or wireless LAN systems.

SUMMARY OF THE INVENTION

To address the above-discussed deficiencies of the prior art, the present invention provides, for use with a wireless computer network having a plurality of access points, a mobile station adapted for communicating with the network via a current access point and having a scanning circuit for locating a new access point, the scanning circuit requiring a scanning period of time to locate the new access point, a method of operation of the mobile station and a wireless computer network infrastructure. The mobile station comprises: (1) a detection circuit that generates a ready-to-scan signal indicating that the mobile station is about to activate the scanning circuit and (2) a suspension circuit, coupled to the detection circuit, that receives the ready-to-scan signal and generates, in response thereto, a data suspend signal for transmission to the current access point, the data suspend signal causing the current access point to suspend transmission of data to the mobile station, thereby preventing loss of the data during the scanning period.

The present invention therefore introduces a system by which the mobile station can instruct the network (via the current access point) to suspend transmission of data to the mobile station while the mobile station is scanning to locate a new access point (an initial step in the handover process). Transmission of the data may be suspended only during the scanning period, or may extend to beyond the scanning period.

In one embodiment of the present invention, the current access point buffers the data during the scanning period. Local buffering of the data in the current access point allows efficient transmission after the scanning period has concluded. Of course, buffering is not necessary to the broad scope of the invention. The data may instead be retransmitted from its source within the network to the mobile station through the current access point, the new access point or some other access point.

In one embodiment of the present invention, the data suspend signal is a power save mode enable signal conforming to an IEEE 802.11 Air Interface protocol. The IEEE 802.11 protocol provides a power save mode signal, allowing a mobile station to enter a so-called "DOZE" state. During the mobile station's "DOZE" state, the current access point suspends transmission of any data destined for the mobile station until such time as the mobile station signals its awakening. The present invention can take advantage of this provision, "tricking" the current access point into suspending transmission during the scanning period, although the mobile station is not in a "DOZE" state.

In one embodiment of the present invention, the detection circuit is further capable of generating a scan-complete signal, the suspension circuit generating, in response thereto, a data resume signal for transmission to the current access point, the data resume signal causing the current access point to resume transmission of data to the mobile station. Once the scanning period is over, the detection circuit and suspension circuit preferably reestablish transmission of the data.

In one embodiment of the present invention, the suspension circuit is further capable of polling the current access point to cause the current access point to transmit the data to the mobile station. Once the scanning period is over, the current access point may be polled for data that would have been transmitted during the scanning period. Of course, the polling does not need to occur immediately after the scanning period is over. Further, the data need not have been buffered. However, if the data are buffered, the scanning and subsequent handover process appears "seamless" to both the network and the mobile station.

In one embodiment of the present invention, the suspension circuit is further capable of transmitting a data resume signal, the data resume signal being a power save mode disable signal and a polling signal conforming to the IEEE 802.11 Air Interface protocol. As above, the present invention can take advantage of the IEEE 802.11 protocol to cause transmission to resume.

In one embodiment of the present invention, the scanning circuit is a frequency scanning circuit. A wireless computer network infrastructure to be illustrated and described comprises a plurality of access points operating at various frequencies. The scanning circuitry within the mobile unit can therefore change frequencies to communicate with selected access points to determine their suitability as a new access point. This need not be the case, however. The mobile station can communicate with selected access points by means of a unique digital code or by any one of other conventional addressing schemes.

The foregoing has outlined, rather broadly, preferred and alternative features of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis for designing or modifying other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates a topological diagram of a wireless computer network;

FIG. 2 illustrates a diagram of an access point and a mobile station of the wireless computer network of FIG. 1;

FIGS. 3A-3C illustrate message frames according to an IEEE 802.11 protocol that the mobile station of FIG. 2 may employ to transmit buffering messages to the access point of FIG. 2; and

FIG. 4 illustrates a flow diagram of a method for providing seamless handover in a wireless computer network.

DETAILED DESCRIPTION

Referring initially to FIG. 1, illustrated is the topology of wireless computer network 10. Server 20 of wireless network 10 communicates bi-directionally with access points 40-42 via bus 30, which is typically a hard-wired connection. In other embodiments, server 20 may communicate with one or more of access points 40-42 by wireless link. AP 40-42 also communicate with one or more mobile stations (MS) 50-53 by wireless link. Each access point can transmit data to and receive data from mobile stations that are within the specified broadcast range of the access point. For example, AP 40 and AP 41 have broadcast ranges 60 and 61, respectively. AP 40 can communicate with MS 50 and MS 51 and AP 41 can communicate with MS 52 and MS 53.

Although the exemplary broadcast coverage areas of AP 40 and AP 41 are circular in shape, it is possible for the broadcast area of an access point to assume other shapes, including hexagonal. The shape and size of the coverage area of an access point is frequently determined by obstructions that prevent the transmission of signals between the access point and a mobile station.

Following the release of the ISM bands, wireless computer networks have been implemented in a wide variety of systems. For example, network 10 may be a wireless LAN in an office building. Mobile stations 50-53 would typically be desktop and/or notebook computers that communicate with a document server, such as server 20, or run payroll or spreadsheet applications in connection with a server. Alternatively, network 10 may be a wireless LAN used to run the operations of a warehouse facility or manufacturing plant. Employees roaming the warehouse or factory floor, or even moving outside the facility, could communicate with a central server using a wide variety of mobile stations. For example, employees could use bar code scanners to send and receive data to/from server 20 through AP 40-42. Still other employees may roam a facility using notepad devices to update inventory in server 20. In still other embodiments, network 10 may a wireless LAN in a large department store and mobile stations 50-54 could be electronic cash registers and/or bar code readers.

As mobile stations 50-53 move about in the wireless LAN environment, the mobile stations will enter and leave the coverage areas of different access points. For example, as MS 50 moves in the direction of path 70, MS 50 moves away from its current access point, AP 40, to a new access point, AP 41. At some point in its movement along path 70, MS 50 determines that the signal quality of the link with current AP 40 has degraded below (or at least close to) an acceptable threshold level. When this occurs, MS 50 begins scanning for another AP in order to set up a "handover".

If current AP 40 attempts to transmit data to MS 50 during the scanning period, the data will be lost. To prevent this, the present invention takes advantage of a power saving protocol provision that is common in the power management scheme of many wireless systems. For example, in a computer network operating under the IEEE 802.11 wireless protocol, a mobile station may transmit a message to its current access point indicating that the mobile station is going into a "DOZE" state. This generally indicates that the mobile station is being turned off, or taken off-line, by the user. During the "DOZE" state of a mobile station, the access point buffers any messages destined for the mobile station in a designated power save queue until such time as the mobile station user comes back on-line and switches the power saver mode to "ACTIVE." At that point, the access point transmits all of the buffered messages that were received during the "DOZE" state of the mobile station.

Turning now to FIG. 2, illustrated is a more detailed diagram of access point 40 and mobile station 50 of the wireless computer network of FIG. 1. MS 50 comprises power save control circuit 92, transceiver (XCVR) 90 and roam control circuit 94. AP 40 comprises power save queue 80 and transceiver (XCVR) 82. XCVR 82 and XCVR 90 provide communication between MS 50 and AP 40. Roam control circuit 94 of MS 50 monitors the quality of the signal received by XCVR 90 to determine whether or not it is necessary to initiate handover to another AP. When the signal falls below (or even close to) a minimum threshold level, roam control circuit 94 sends a ready-to-scan signal to power save control circuit 92.

Power save control circuit 92 responds to the ready-to-scan signal by sending a message to AP 40 that indicates that MS 50 is entering a power save mode and that new messages should be stored in power save queue 80. For example, in a wireless LAN operating under IEEE 802.11 protocol, power save control circuit 92 sends to AP 40 a standard NULL message with the power management (PM) bits in the header set to "PS" value (i.e., power save mode). In response, AP 40 stores all messages sent by server 20 and/or other network devices in power save queue 80 while MS 50 is in the "DOZE" state. Alternatively, AP 40 may refuse to accept data sent by server 20 and/or other network devices. Server 20 (or another network device) may then retransmit the data at a later time when MS 50 is back on-line.

While AP 40 is buffering data intended for MS 50 (or refusing to accept same), XCVR 90 of MS 50 scans for another AP. XCVR 90 may scan predetermined channels or scan randomly. When the scanning cycle is complete (whether successful or unsuccessful), XCVR 90 switches back to the frequency channel used by AP 40 and MS 50 transmits a message to AP 40 indicating that MS 50 has re-entered the active mode and that any messages stored during the "DOZE" state should be downloaded to MS 50. For example, in a wireless LAN operating under IEEE 802.11 protocol, at the end of the scan period, power save control circuit 92 sends to AP 40 a standard PS-POLL message with the power management (PM) bits in the header set to "A" value (i.e., active mode). AP 40 then ceases buffering messages for MS 50 and transmits all previously buffered messages.

Turning now to FIG. 3A, illustrated is a Medium Access Control (MAC) general frame format in accordance with IEEE 802.11 specification. The first seven fields, Frame Control, Duration/ID, Address 1-Address 4 and Sequence Control, comprise the MAC header set. The header set is followed by a Frame Body of up to 2312 data bytes and a CRC field. The first field of the header set is the Frame Control field, which is illustrated in greater detail in FIG. 3B. The thirteenth bit of the Frame Control field is the Power Management bit, which is used to indicate the power management mode of a mobile station. The value of the Power Management remains constant in each frame from a particular mobile station within a frame sequence. The value indicates the mode in which the station shall be after the successful completion of the frame exchange sequence. A value of 1 indicates that the mobile station shall be in Power Saver mode. A value of 0 indicates that the mobile station shall be in Active mode. The Power Management field is always set to 0 in frames transmitted by an access point.

A NULL frame is a particular type of MAC frame in which the two bits of the Type field are set to "10" and the four bits of the subtype field are set to "0100". By setting the Power Saver mode bit to 1 in a NULL frame, a mobile station can indicate (falsely) to an access point that the mobile station is entering the "DOZE" state and then begin a scanning operation while the access point buffers data.

Turning now to FIG. 3C, illustrated is a MAC PS-POLL frame format in accordance with IEEE 802.11 specification. The first four field, Frame Control, SID, BSS ID and TA, comprise the MAC header set. The Frame Control field of the PS-POLL frame has the same format as the Frame Control field illustrated in FIG. 3B. By setting the Power Saver mode bit to 0 in a PS-POLL message frame, a mobile station can exit the "DOZE" state and alert an access point that it is ready to receive buffered data.

Turning now to FIG. 4, illustrated is flow diagram 400 of a method for providing seamless handover in a wireless computer network operating in accordance with an IEEE 802.11 protocol. Initially, in step 401, MS 50 is operating in the active mode of the standard Power Management (PM) scheme. In step 402, MS 50 iteratively monitors the quality of the wireless link with current AP 40. If the link quality remains above the threshold value, MS 50 returns to Step 401 and remains in the active mode.

However, if the link quality falls below (or even close to) the threshold level, MS 50 sends a NULL message to AP 40 with the power management bits set to "PS" (Step 403). This causes AP 40 to begin storing messages destined for MS 50 in a power management queue. MS 50 then scans for other access points operating in the same or in different frequency channels (step 404). After some time period of scanning, MS 50 will set XCVR 90 back to the frequency channel of current AP 40 (Step 405). This is done whether or not MS 50 has found a better AP signal. MS 50 then sends a power save poll (PS-POLL) message to current AP 40 with the power management bits in the header set to "A" (active mode).

In response to the PS-POLL message, AP 40 send any messages stored in the power management queue in power save queue 80 to MS 50 (Step 406). Once all of the messages are transferred, MS 50 switches to a new AP, if a new AP with a better quality link was found during the scanning period and resumes normal operation with the new AP (Steps 407, 408 and 401). If a better link was not found during the scanning period, MS 50 continues to communicate with current AP 40 (Steps 407 and 401).

Although the present invention has been described in detail, those skilled in the art should understand that they can make various changes, substitutions and alterations herein without departing from the spirit and scope of the invention in its broadest form.

Citations de brevets
Brevet cité Date de dépôt Date de publication Déposant Titre
US5339316 *2 avr. 199316 août 1994Ncr CorporationWireless local area network system
US5465392 *17 mai 19947 nov. 1995At&T Global Information Solutions CompanyApparatus and method for operating a wireless local area network having power conservation
US5570084 *28 juin 199429 oct. 1996Metricom, Inc.Method of loose source routing over disparate network types in a packet communication network
US5570366 *18 mai 199529 oct. 1996International Business Machines CorporationBroadcast/multicast filtering by the bridge-based access point
US5572528 *20 mars 19955 nov. 1996Novell, Inc.Mobile networking method and apparatus
US5673031 *5 juil. 199430 sept. 1997Norand CorporationRedundant radio frequency network having a roaming terminal communication protocol
US5724346 *18 sept. 19953 mars 1998Fujitsu LimitedMeans for maintaining connectable access points owing to movement of a mobile station between cells in a wireless LAN system
US5768531 *27 mars 199516 juin 1998Toshiba America Information SystemsApparatus and method for using multiple communication paths in a wireless LAN
US5774461 *27 sept. 199530 juin 1998Lucent Technologies Inc.Medium access control and air interface subsystem for an indoor wireless ATM network
US5815811 *27 oct. 199529 sept. 1998Symbol Technologies, Inc.Preemptive roaming in a cellular local area wireless network
US5822361 *8 nov. 199513 oct. 1998Hitachi, Ltd. And Hitachi Microcomputer System Ltd.Wireless LAN system and base station apparatus
Référencé par
Brevet citant Date de dépôt Date de publication Déposant Titre
US6272541 *8 oct. 19987 août 2001International Business Machines CorporationData processing system and method for determining a physical location of a client computer system coupled to a server via a physical network
US6304899 *8 oct. 199816 oct. 2001International Business Machines CorporationData processing system and method for powering-on a remote client computer system utilizing a wireless signal
US6477373 *10 août 20005 nov. 2002Research Foundation Of State University Of New YorkMethod and apparatus to maintain connectivity for mobile terminals in wireless and cellular communications systems
US6510153 *19 févr. 199921 janv. 2003Kabushiki Kaisha ToshibaMobile IP communication scheme using dynamic address allocation protocol
US6590884 *7 janv. 19998 juil. 2003Texas Instruments IncorporatedMethod and apparatus providing spatial diversity within an indoor network
US667473817 sept. 20016 janv. 2004Networks Associates Technology, Inc.Decoding and detailed analysis of captured frames in an IEEE 802.11 wireless LAN
US6693888 *6 juin 200117 févr. 2004Networks Associates Technology, Inc.Method and apparatus for filtering that specifies the types of frames to be captured and to be displayed for an IEEE802.11 wireless LAN
US6704561 *12 déc. 20009 mars 2004Nec Infrontia CorporationPower management system for use with wireless LAN terminal unit
US6760318 *11 janv. 20026 juil. 2004Airflow NetworksReceiver diversity in a communication system
US678865811 janv. 20027 sept. 2004Airflow NetworksWireless communication system architecture having split MAC layer
US6791962 *29 janv. 200314 sept. 2004Globespan Virata, Inc.Direct link protocol in wireless local area networks
US6816493 *9 mars 20019 nov. 2004Motorola, Inc.Method and apparatus employing a mediation device to facilitate communication among devices in an asynchronous communications network
US6839331 *5 mars 20014 janv. 2005Sharp Laboratories Of America, Inc.Method to dynamically change all MIB parameters of a wireless data network
US686244811 janv. 20021 mars 2005Broadcom CorporationToken-based receiver diversity
US6870822 *20 févr. 200122 mars 2005Nokia CorporationMethod and equipment for supporting mobility in a telecommunication system
US69342741 juil. 200223 août 2005Kabushiki Kaisha ToshibaMobile IP communication scheme using dynamic address allocation protocol
US694748328 déc. 200020 sept. 2005Nortel Networks LimitedMethod, apparatus, and system for managing data compression in a wireless network
US6961762 *10 mai 20001 nov. 2005Sygate Technologies, Inc.Automatic switching network points based on configuration profiles
US70201201 juil. 200228 mars 2006Kabushiki Kaisha ToshibaMobile IP communication scheme using dynamic address allocation protocol
US7079850 *23 mars 200318 juil. 2006Accenture Global Services GmbhLocalization of radio-frequency transceivers
US7103028 *19 juil. 19995 sept. 2006Matsushita Electric Industrial Co., Ltd.Radio communication system, and gateways, radio intelligent terminals and radio communication methods applied thereto
US71134985 juin 200226 sept. 2006Broadcom CorporationVirtual switch
US7130289 *14 mars 200231 oct. 2006Airmagnet, Inc.Detecting a hidden node in a wireless local area network
US714919611 janv. 200212 déc. 2006Broadcom CorporationLocation tracking in a wireless communication system using power levels of packets received by repeaters
US7158778 *11 avr. 20022 janv. 2007Intel CorporationMethod for virtual network connectivity for powered off stations in wireless LAN networks
US7159042 *29 févr. 20002 janv. 2007Canon Kabushiki KaishaMethod and device for communicating a message on a network and systems using them
US717120614 août 200130 janv. 2007Koninklijke Philips Electronics, N.V.Method and system for transferring a communication session
US717147619 avr. 200230 janv. 2007Motorola, Inc.Protocol and structure for self-organizing network
US71739229 févr. 20016 févr. 2007Symbol Technologies, Inc.Multiple wireless local area networks occupying overlapping physical spaces
US717392325 oct. 20016 févr. 2007Symbol Technologies, Inc.Security in multiple wireless local area networks
US723647015 sept. 200326 juin 2007Broadcom CorporationTracking multiple interface connections by mobile stations
US725122218 déc. 200131 juil. 2007Motorola, Inc.Procedures for merging the mediation device protocol with a network layer protocol
US7269448 *9 nov. 200111 sept. 2007Electronics And Telecommunications Research InstituteMethod for recognizing request for data transmission by mobile/base station RRC using network transfer device
US7280495 *28 déc. 20009 oct. 2007Nortel Networks LimitedReliable broadcast protocol in a wireless local area network
US730827928 déc. 200011 déc. 2007Nortel Networks LimitedDynamic power level control on transmitted messages in a wireless LAN
US733989228 déc. 20004 mars 2008Nortel Networks LimitedSystem and method for dynamic control of data packet fragmentation threshold in a wireless network
US7353416 *25 juil. 20011 avr. 2008Hewlett-Packard Development Company, L.P.Wireless access point seek mode for wireless access clients
US736610328 déc. 200029 avr. 2008Nortel Networks LimitedSeamless roaming options in an IEEE 802.11 compliant network
US737607928 mai 200420 mai 2008Symbol Technologies, Inc.Backup cell controller
US7430604 *20 févr. 200130 sept. 2008Nokia CorporationMethod and equipment for accessing a telecommunication network
US744046222 mai 200321 oct. 2008Motorola, Inc.Quality of service (QOS) control mechanisms using mediation devices in an asynchronous network
US7447177 *26 août 20034 nov. 2008Intel CorporationMethod and apparatus of secure roaming
US7450544 *5 févr. 200311 nov. 2008Samsung Electronics Co., Ltd.Apparatus and method for supporting mobility between subnetworks of mobile node in wireless LAN
US749277322 mai 200317 févr. 2009Motorola, Inc.Media access control and distributed data processing using mediation devices in an asynchronous network
US750234922 nov. 200610 mars 2009Proxim Wireless CorporationSystem and method for sending data to a mobile device in a wireless network
US751555725 avr. 20027 avr. 2009Broadcom CorporationReconfiguration of a communication system
US75618983 déc. 200414 juil. 2009Samsung Electronics Co., Ltd.Apparatus and method for registering wireless terminals with access point through wireless network
US757092716 juin 20064 août 2009Motorola, Inc.Decentralized wireless communication network and method having a plurality of devices
US75900792 oct. 200315 sept. 2009Motorola, Inc.Method of communication device initiated frame exchange
US7593417 *21 janv. 200522 sept. 2009Research In Motion LimitedHandling broadcast and multicast traffic as unicast traffic in a wireless network
US7593718 *31 déc. 200222 sept. 2009Motorola, Inc.WLAN communication system and method with mobile base station
US759930915 sept. 20056 oct. 2009Samsung Electronics Co., Ltd.Method and apparatus for managing cell-by-cell demodulation timings of a user equipment in an asynchronous mobile telecommunication system
US761319618 janv. 20053 nov. 2009Cisco Technology, Inc.Distributed network communication system which selectively provides data to different network destinations
US764346025 sept. 20065 janv. 2010Broadcom CorporationDistributed MAC architecture for a wireless repeater
US765303323 févr. 200426 janv. 2010Symbol Technologies, Inc.Infrastructure for wireless LANs
US766854216 févr. 200523 févr. 2010Broadcom CorporationToken-based receiver diversity
US7672248 *13 juin 20062 mars 2010Scenera Technologies, LlcMethods, systems, and computer program products for automatically changing network communication configuration information when a communication session is terminated
US767227425 avr. 20022 mars 2010Broadcom CorporationMobility support via routing
US768921012 sept. 200330 mars 2010Broadcom CorporationPlug-n-playable wireless communication system
US7697470 *29 déc. 200413 avr. 2010Broadcom CorporationUtilization of the internet protocol to facilitate communication involving mobile devices
US7701912 *19 mai 200420 avr. 2010Cisco Technology, Inc.System and method for concurrently utilizing multiple system identifiers
US77424453 mars 200422 juin 2010Cisco Technology, Inc.Distributed network communication system which enables multiple network providers to use a common distributed network infrastructure
US774778317 févr. 200629 juin 2010Canon Kabushiki KaishaMethod and device for communicating a message on a network and systems using them
US7752330 *29 oct. 20076 juil. 2010International Business Machines CorporationSystem for low power operation of wireless LAN interfaces
US7756082 *6 mai 200213 juil. 2010Atheros Communications, Inc.Wireless LAN using background scanning technique
US7782886 *19 août 200524 août 2010Nec CorporationMethod for improving quality of service in a wireless network
US7813295 *10 janv. 200712 oct. 2010Broadcom CorporationCo-location interference avoidance in multiple protocol communication networks
US784068911 avr. 200623 nov. 2010Wayport, Inc.Dynamically modifying the display of a computing device to provide advertisements
US785665911 mars 200321 déc. 2010Wayport, Inc.System and method for user access to a distributed network communication system using persistent identification of subscribers
US7876699 *27 nov. 200725 janv. 2011Hon Hai Precision Industry Co., Ltd.Mobile station and method for verifying access points thereof
US787670412 sept. 200325 janv. 2011Broadcom CorporationTunneling protocols for wireless communications
US7881322 *28 juil. 20051 févr. 2011Avaya Inc.Power-saving mechanism for periodic traffic streams in wireless local-area networks
US792051823 févr. 20095 avr. 2011Cisco Technology, Inc.System and method for concurrently utilizing multiple system identifiers
US793329330 juin 200426 avr. 2011Xocyst Transfer Ag L.L.C.Link margin notification using return frame
US79489511 nov. 200424 mai 2011Xocyst Transfer Ag L.L.C.Automatic peer discovery
US795774110 juil. 20097 juin 2011Broadcom CorporationToken-based receiver diversity
US7969937 *23 mars 200428 juin 2011Aruba Networks, Inc.System and method for centralized station management
US7991425 *8 oct. 20082 août 2011Hon Hai Precision Industry Co., Ltd.Mobile terminal device and roaming method thereof
US800122314 août 200916 août 2011Symantec CorporationAutomatic switching network points based on configuration profiles
US8001263 *19 juin 200816 août 2011Lg ElectronicsMethod for suspending and resuming content transmission/reception
US8001264 *7 juil. 200916 août 2011Lg Electronics Inc.Method for suspending and resuming content transmission/reception
US800503221 janv. 200523 août 2011Research In Motion LimitedMaintaining delivery traffic indication message (DTIM) periods on a per-wireless client device basis
US802732011 avr. 200727 sept. 2011Symbol Technologies, Inc.Wireless local area networks
US802763712 sept. 200327 sept. 2011Broadcom CorporationSingle frequency wireless communication system
US803619511 mars 201011 oct. 2011Cisco Technology, Inc.System and method for concurrently utilizing multiple system identifiers
US80502408 juin 20051 nov. 2011Symbol Technologies, Inc.Multiple wireless local area networks occupying overlapping physical spaces
US805036030 juin 20041 nov. 2011Intellectual Ventures I LlcDirect link relay in a wireless network
US806438025 févr. 200922 nov. 2011Broadcom CorporationReconfiguration of a communication system
US809564725 oct. 200710 janv. 2012Wayport, Inc.Method and apparatus for geographic-based communications service
US809567126 août 200810 janv. 2012Nokia CorporationMethod and equipment for accessing a telecommunication network
US8102801 *7 janv. 201024 janv. 2012Interdigital Technology CorporationUser equipment for physical layer automatic repeat request
US81446402 nov. 200627 mars 2012Broadcom CorporationLocation tracking in a wireless communication system using power levels of packets received by repeaters
US8161302 *10 avr. 200917 avr. 2012Samsung Electronics Co., LtdMethod and apparatus for data transmission in wireless local access network and system therefor
US8189538 *29 janv. 201029 mai 2012Broadcom CorporationReconfiguration of a communication system
US819973329 oct. 200712 juin 2012Wayport, Inc.Method and apparatus for geographic-based communications service
US82501673 mars 200421 août 2012Cisco Technology, Inc.Distributed network communication system which enables multiple network providers to use a common distributed network infrastructure
US825020425 oct. 200721 août 2012Wayport, Inc.Method and apparatus for geographic-based communications service
US831564023 déc. 200920 nov. 2012Wi-Lan, Inc.Methods and systems for transmission of multiple modulated signals over wireless networks
US833138327 oct. 200911 déc. 2012Cisco Technology, Inc.Distributed network communication system which selectively provides data to different network destinations
US83553581 déc. 200915 janv. 2013Broadcom CorporationDistributed MAC architecture for wireless repeater
US8363596 *8 août 200929 janv. 2013Research In Motion LimitedPower saving via variable listen intervals in a WLAN
US836483114 oct. 201129 janv. 2013Nokia CorporationMethod and equipment for accessing a telecommunication network
US837414812 nov. 200312 févr. 2013Samsung Electronics Co., Ltd.Handoff method in wireless LAN, and access point and mobile station performing handoff method
US839125611 janv. 20075 mars 2013Symbol Technologies, Inc.RF port for multiple wireless local area networks
US841776311 févr. 20049 avr. 2013Wayport, Inc.Providing information to a computing device based on known location and user information
US842241719 sept. 200716 avr. 2013Microsoft CorporationMethod of broadcasting and multicasting using satellite medium
US844693312 oct. 201121 mai 2013Intellectual Ventures I LlcDirect link relay in a wireless network
US845706111 oct. 20114 juin 2013Wi-LanMethod and system for adaptively obtaining bandwidth allocation requests
US84571451 juin 20124 juin 2013Wi-Lan, Inc.Method and apparatus for bandwidth request/grant protocols in a wireless communication system
US846272318 avr. 201111 juin 2013Wi-Lan, Inc.Methods and systems for transmission of multiple modulated signals over wireless networks
US846276113 oct. 201111 juin 2013Wi-Lan, Inc.Method and system for adaptively obtaining bandwidth allocation requests
US846280912 févr. 200911 juin 2013Wi-Lan, Inc.Method and system for adaptively obtaining bandwidth allocation requests
US846281012 févr. 200911 juin 2013Wi-Lan, Inc.Method and system for adaptively obtaining bandwidth allocation requests
US847888727 mars 20062 juil. 2013Wayport, Inc.Providing advertisements to a computing device based on a predetermined criterion of a wireless access point
US849827811 janv. 200730 juil. 2013Symbol Technologies, Inc.System for multiple wireless local area networks
US850924625 oct. 200713 août 2013Wayport, Inc.Method and apparatus for geographic-based communications service
US8526950 *30 déc. 20033 sept. 2013Nokia CorporationDetermining handover based on state of mobile terminal
US856683914 mai 201022 oct. 2013William J. JohnsonSystem and method for automated content presentation objects
US85837238 oct. 201212 nov. 2013Wayport, Inc.Receiving location based advertisements on a wireless communication device
US858813012 avr. 200619 nov. 2013Wayport, Inc.Distributed network communication system to provide wireless access to a computing device at a reduced rate
US860034114 mars 20083 déc. 2013William J. JohnsonSystem and method for location based exchanges of data facilitating distributed locational applications
US86068516 déc. 201110 déc. 2013Wayport, Inc.Method and apparatus for geographic-based communications service
US8615020 *13 oct. 201124 déc. 2013Wi-Lan, Inc.Method and system for adaptively obtaining bandwidth allocation requests
US862741618 juin 20127 janv. 2014Wayport, Inc.Device-specific authorization at distributed locations
US863112817 juil. 201214 janv. 2014Wayport, Inc.Method and apparatus for geographic-based communications service
US863479613 nov. 200921 janv. 2014William J. JohnsonSystem and method for location based exchanges of data facilitating distributed location applications
US86392673 oct. 200828 janv. 2014William J. JohnsonSystem and method for location based exchanges of data facilitating distributed locational applications
US865466418 avr. 201118 févr. 2014Wi-Lan, Inc.Methods and systems for transmission of multiple modulated signals over wireless networks
US866589828 janv. 20104 mars 2014Wi-Lan, Inc.Method and system for adaptively obtaining bandwidth allocation requests
US86876108 déc. 20091 avr. 2014Symbol Technologies, Inc.Infrastructure for wireless LANS
US869936713 mai 201115 avr. 2014Qualcomm IncorporatedWireless LAN using transmission monitoring
US869947311 janv. 200715 avr. 2014Symbol Technologies, Inc.Cell controller for multiple wireless local area networks
US869947411 janv. 200715 avr. 2014Symbol Technologies, Inc.System with a cell controller adapted to perform a management function
US871859821 août 20136 mai 2014William J. JohnsonSystem and method for location based exchange vicinity interest specification
US875027224 juin 201110 juin 2014Aruba Networks, Inc.System and method for centralized station management
US875082323 sept. 201310 juin 2014William J. JohnsonSystem and method for location based exchanges of data facilitating distributed locational applications
US876180423 sept. 201324 juin 2014William J. JohnsonSystem and method for location based exchanges of data facilitating distributed locational applications
US878792411 oct. 201222 juil. 2014Wi-Lan, Inc.Methods and systems for transmission of multiple modulated signals over wireless networks
US878798814 janv. 200522 juil. 2014Intellectual Ventures I LlcPower management for wireless direct link
US8804655 *4 févr. 200812 août 2014Samsung Electronics Co., Ltd.Wireless LAN network, and mobile station, base station and method of controlling handoff in wireless LAN network to prevent packet loss during handoff
US88435155 févr. 201323 sept. 2014Snap Trends, Inc.Methods and systems of aggregating information of social networks based on geographical locations via a network
US888622623 sept. 201311 nov. 2014William J. JohnsonSystem and method for timely whereabouts determination by a mobile data processing system
US88871778 juil. 201311 nov. 2014William J. JohnsonSystem and method for automated content distribution objects
US889273630 mai 201318 nov. 2014Wayport, Inc.Providing an advertisement based on a geographic location of a wireless access point
US889774121 août 201325 nov. 2014William J. JohnsonSystem and method for mobile device usability by locational conditions
US889774221 août 201325 nov. 2014William J. JohnsonSystem and method for sudden proximal user interface
US892380621 août 201330 déc. 2014William J. JohnsonSystem and method for presenting application data by data processing system(s) in a vicinity
US89250474 déc. 201330 déc. 2014Wayport, Inc.Device-specific authorization at distributed locations
US892990523 déc. 20136 janv. 2015Wi-Lan, Inc.Methods and systems for transmission of multiple modulated signals over wireless networks
US89299156 mars 20136 janv. 2015Wayport, Inc.Providing information to a computing device based on known location and user information
US894269318 mars 201427 janv. 2015William J. JohnsonSystem and method for targeting data processing system(s) with data
US894273222 nov. 201327 janv. 2015William J. JohnsonLocation based exchange operating system
US894273322 nov. 201327 janv. 2015William J. JohnsonSystem and method for location based exchanges of data facilitating distributed location applications
US899028723 sept. 201324 mars 2015Wayport, Inc.Providing promotion information to a device based on location
US900241516 janv. 20147 avr. 2015Intellectual Ventures I LlcPower management for wireless direct link
US901465821 août 201321 avr. 2015William J. JohnsonSystem and method for application context location based configuration suggestions
US901991130 avr. 201228 avr. 2015Aruba Networks, Inc.System and method for centralized station management
US90365536 déc. 201219 mai 2015Blackberry LimitedPower saving via variable listen intervals in a WLAN
US905540622 nov. 20139 juin 2015William J. JohnsonServer-less synchronized processing across a plurality of interoperating data processing systems
US907809521 août 20137 juil. 2015William J. JohnsonSystem and method for location based inventory management
US908886822 nov. 201321 juil. 2015William J. JohnsonLocation based exchange permissions
US908886922 nov. 201321 juil. 2015William J. JohnsonSystem and method for application search results by locational conditions
US910079222 nov. 20134 août 2015William J. JohnsonSystem and method for service-free location based applications
US911329517 juin 201418 août 2015William J. JohnsonSystem and method for location based exchange vicinity interest specification
US9179394 *11 oct. 20073 nov. 2015Stmicroelectronics, Inc.Apparatus and method for coordinated sensing of wireless devices in a communication system
US920427524 nov. 20141 déc. 2015William J. JohnsonSystem and method for targeting data processing system(s) with data
US925359722 nov. 20132 févr. 2016William J. JohnsonSystem and method for determining mobile users of interest
US935130023 mai 201324 mai 2016Wi-Lan, Inc.Method and apparatus for bandwidth request/grant protocols in a wireless communication system
US939240822 nov. 201312 juil. 2016William J. JohnsonSystem and method for location based exchanges of data facilitating distributed locational applications
US940225012 juin 201526 juil. 2016Wi-Lan, Inc.Methods and systems for transmission of multiple modulated signals over wireless networks
US941436824 oct. 20149 août 2016Wi-Lan, Inc.Methods and systems for transmission of multiple modulated signals over wireless networks
US942057324 oct. 201416 août 2016Wi-Lan, Inc.Methods and systems for transmission of multiple modulated signals over wireless networks
US942057412 juin 201516 août 2016Wi-Lan, Inc.Methods and systems for transmission of multiple modulated signals over wireless networks
US943284831 janv. 201230 août 2016Aruba Networks, Inc.Band steering for multi-band wireless clients
US944523813 nov. 201513 sept. 2016William J. JohnsonSystem and method for confirming data processing system target(s)
US945630328 juin 201527 sept. 2016William J. JohnsonSystem and method for service access via hopped wireless mobile device(s)
US947799127 août 201325 oct. 2016Snap Trends, Inc.Methods and systems of aggregating information of geographic context regions of social networks based on geographical locations via a network
US949774312 juin 201515 nov. 2016Wi-Lan, Inc.Methods and systems for transmission of multiple modulated signals over wireless networks
US950333212 nov. 201222 nov. 2016Cisco Technology, Inc.Distributed network communication system which selectively provides data to different network destinations
US95849931 août 201628 févr. 2017William J. JohnsonSystem and method for vector processing on behalf of image aperture aim
US959163923 mai 20137 mars 2017Wi-Lan, Inc.Method and apparatus for bandwidth request/grant protocols in a wireless communication system
US960312931 janv. 201421 mars 2017Wi-Lan, Inc.Methods and systems for transmission of multiple modulated signals over wireless networks
US960314520 mai 201621 mars 2017Wi-Lan, Inc.Method and apparatus for bandwidth request/grant protocols in a wireless communication system
US962644614 nov. 201218 avr. 2017Snap Trends, Inc.Methods and systems of advertising based on aggregated information of social networks within geographical locations via a network
US964860012 juin 20159 mai 2017Wi-Lan, Inc.Methods and systems for transmission of multiple modulated signals over wireless networks
US981402622 juil. 20147 nov. 2017Wi-Lan Inc.Methods and systems for transmission of multiple modulated signals over wireless networks
US20010004594 *12 déc. 200021 juin 2001Nec CorporationPower management system for use with wireless LAN terminal unit
US20010023446 *20 févr. 200120 sept. 2001Peter BaloghMethod and equipment for accessing a telecommunication network
US20010024953 *20 févr. 200127 sept. 2001Peter BaloghMethod and equipment for supporting mobility in a telecommunication system
US20020022483 *22 janv. 200121 févr. 2002Wayport, Inc.Distributed network communication system which allows multiple wireless service providers to share a common network infrastructure
US20020085631 *28 déc. 20004 juil. 2002Engwer Darwin A.Method, apparatus, and system for managing data compression in a wireless network
US20020131371 *5 mars 200119 sept. 2002Sharp Laboratories Of America, Inc.Method to dynamically change all MIB parameters of a wireless data network
US20020167922 *1 juil. 200214 nov. 2002Kabushiki Kaisha ToshibaMobile IP communication scheme using dynamic address allocation protocol
US20020176383 *1 juil. 200228 nov. 2002Kabushiki Kaisha ToshibaMobile IP communication scheme using dynamic address allocation protocol
US20020196763 *22 mai 200226 déc. 2002Reynolds Russell R.Wireless network system software protocol
US20030007461 *18 déc. 20019 janv. 2003Priscilla ChenProcedures for merging the mediation device protocol with a network layer protocol
US20030023761 *25 juil. 200130 janv. 2003Jeansonne Jeffrey K.Wireless access point seek mode for wireless access clients
US20030093535 *9 nov. 200115 mai 2003Jihyuk ChoiMethod for recognizing request for data transmission by mobile/base station RRC using network transfer device
US20030112820 *25 oct. 200119 juin 2003Robert BeachSecurity in multiple wireless local area networks
US20030174680 *14 mars 200218 sept. 2003Chia-Chee KuanDetecting a hidden node in a wireless local area network
US20030185172 *5 févr. 20032 oct. 2003Seon-Soo RueApparatus and method for supporting mobility between subnetworks of mobile node in wireless LAN
US20030186679 *27 mars 20022 oct. 2003International Business Machines CorporationMethods, apparatus and program product for monitoring network security
US20030193895 *28 déc. 200016 oct. 2003Engwer Darwin A.Seamless roaming options in an IEEE 802.11 compliant network
US20030224775 *20 nov. 20024 déc. 2003Nec CorporationRadio access communication system capable of preventing packet loss
US20030227893 *5 juin 200211 déc. 2003Zeljko BajicVirtual switch
US20030231597 *22 mai 200318 déc. 2003Hester Lance EricQuality of service (QoS) control mechanisms using mediation devices in an asynchronous network
US20030231608 *29 janv. 200318 déc. 2003Wentink Maarten MenzoDirect link protocol in wireless local area networks
US20030233332 *11 mars 200318 déc. 2003Keeler James D.System and method for user access to a distributed network communication system using persistent identification of subscribers
US20030233580 *14 janv. 200318 déc. 2003Keeler James D.Authorization and authentication of user access to a distributed network communication system with roaming features
US20040003111 *19 avr. 20021 janv. 2004Masahiro MaedaProtocol and structure for self-organizing network
US20040018839 *5 juin 200329 janv. 2004Oleg AndricProtocol and structure for mobile nodes in a self-organizing communication network
US20040042501 *22 mai 20034 mars 2004Hester Lance EricMedia access control and distributed data processing using mediation devices in an asynchronous network
US20040081133 *2 oct. 200329 avr. 2004Nattavut SmavatkulMethod of communication device initiated frame exchange
US20040167958 *3 mars 200426 août 2004Stewart Brett B.Distributed network communication system which enables multiple network providers to use a common distributed network infrastructure
US20040170153 *3 mars 20042 sept. 2004Wayport, Inc.Distributed network communication system which enables multiple network providers to use a common distributed network infrastructure
US20040203609 *11 avr. 200214 oct. 2004K.P. SameerVirtual network connectivity for devices in wireless LAN networks
US20040203836 *31 déc. 200214 oct. 2004Gorday Paul E.WLAN communication system and method with mobile base station
US20040214572 *19 mai 200428 oct. 2004Wayport, Inc.System and method for concurrently utilizing multiple system identifiers
US20040224690 *12 nov. 200311 nov. 2004Samsung Electronics Co., Ltd.Handoff method in wireless LAN, and access point and mobile station performing handoff method
US20040255008 *21 avr. 200316 déc. 2004International Business Machines CorporationSystem for low power operation of wireless LAN
US20050028032 *28 mai 20043 févr. 2005John KleinBackup cell controller
US20050030976 *30 juin 200410 févr. 2005Globespan Virata IncorporatedLink margin notification using return frame
US20050036465 *30 juin 200317 févr. 2005Shai WaxmanDevice, system and method of signal detection for wireless network
US20050047361 *26 août 20033 mars 2005Max FudimMethod and apparatus of secure roaming
US20050047381 *26 janv. 20043 mars 2005Proxim Corporation, A Delaware CorporationSystem and method for a topology map related to access point usage in a wireless network
US20050094588 *30 juin 20045 mai 2005Globespan Virata IncorporatedDirect link relay in a wireless network
US20050122921 *3 déc. 20049 juin 2005Cheong-Jeong SeoApparatus and method for registering wireless terminals with access point through wireless network
US20050122927 *14 janv. 20059 juin 2005Conexant, Inc.Power management for wireless direct link
US20050130634 *1 nov. 200416 juin 2005Globespanvirata, Inc.Location awareness in wireless networks
US20050130668 *23 mars 200316 juin 2005Cameron Richard N.Localization of radio-frequency transceivers
US20050135305 *1 nov. 200423 juin 2005Globespanvirata, Inc.Automatic peer discovery
US20050141442 *29 déc. 200430 juin 2005Martin MorrisUtilization of the internet protocol to facilitate communication involving mobile devices
US20050143071 *30 déc. 200330 juin 2005Mikko JaakkolaArranging handover
US20050153719 *16 févr. 200514 juil. 2005Broadcom CorporationToken-based receiver diversity
US20050157690 *28 mai 200421 juil. 2005James FrankWireless network cell controller
US20050157691 *18 janv. 200521 juil. 2005Stewart Brett B.Distributed network communication system which selectively provides data to different network destinations
US20050213579 *23 mars 200429 sept. 2005Iyer Pradeep JSystem and method for centralized station management
US20050226181 *8 juin 200513 oct. 2005Robert BeachMultiple wireless local area networks occupying overlapping physical spaces
US20050261970 *21 mai 200424 nov. 2005Wayport, Inc.Method for providing wireless services
US20060039395 *19 août 200523 févr. 2006Xavier Perez-CostaMethod for improving quality of service in a wireless network
US20060069760 *27 oct. 200530 mars 2006Yuen-Pin YeapAutomatic switching network points based on configuration profiles
US20060136603 *17 févr. 200622 juin 2006Canon Kabushiki KaishaMethod and device for communicating a message on a network and systems using them
US20060165031 *21 janv. 200527 juil. 2006Research In Motion LimitedApparatus and methods for delivery handling broadcast and multicast traffic as unicast traffic in a wireless network
US20060187864 *21 janv. 200524 août 2006Research In Motion LimitedApparatus and methods for delivery traffic indication message (DTIM) periods in a wireless network
US20060190586 *12 avr. 200624 août 2006Stewart Brett BDistributed network communication system to provide wireless access to a computing device at a reduced rate
US20060251040 *15 sept. 20039 nov. 2006Gunnar NitscheMethod for establishing a connection between a mobile station and a communication network
US20070025349 *25 sept. 20061 févr. 2007Broadcom CorporationDistributed MAC architecture for wireless repeater
US20070047484 *2 nov. 20061 mars 2007Broadcom CorporationLocation tracking in a wireless communication system using power levels of packets received by repeaters
US20070104145 *8 nov. 200510 mai 2007Hsiao-Shun JanData accessing method for a wireless communication device performing a handover operation between wireless stations
US20070109973 *10 janv. 200717 mai 2007Broadcom Corporation, A California CorporationCo-location interference avoidance in multiple protocol communication networks
US20070127497 *22 nov. 20067 juin 2007Terabeam. Inc.System and method for sending data to a mobile device in a wireless network
US20070177435 *11 janv. 20072 août 2007Symbol Technologies, Inc.System for multiple wireless local area networks
US20070286215 *13 juin 200613 déc. 2007Robert Paul MorrisMethods, systems, and computer program products for automatically changing network communication configuration information when a communication session is terminated
US20070293237 *16 juin 200620 déc. 2007Motorola, Inc.Device positioning with delegated location determination
US20080039140 *16 oct. 200714 févr. 2008Broadcom CorporationSystem and method for secure biometric identification
US20080046547 *29 oct. 200721 févr. 2008International Business Machines CorporationSystem for Low Power Operation of Wireless LAN Interfaces
US20080052366 *29 oct. 200728 févr. 2008International Business Machines CorporationSystem for low power operation of wireless lan interfaces
US20080052548 *29 oct. 200728 févr. 2008International Business Machines CorporationSystem for low power operation of wireless lan interfaces
US20080064404 *5 sept. 200713 mars 2008Nec (China) Co., Ltd.Methods and device for user terminal based fast handoff
US20080069023 *19 sept. 200720 mars 2008Microsoft CorporationMethod for communicating with multiple network nodes
US20080096542 *11 oct. 200724 avr. 2008Stmicroelectronics, Inc.Apparatus and method for coordinated sensing of wireless devices in a communication system
US20080130542 *27 nov. 20075 juin 2008Hon Hai Precision Industry Co., Ltd.Mobile station and method for verifying access points thereof
US20080176515 *19 janv. 200724 juil. 2008Hiles Paul EWireless hotspot detection system and method
US20080192698 *4 févr. 200814 août 2008Seon-Soo RueWireless LAN network, and mobile station, base station and method of controlling handoff in wireless LAN network
US20080316989 *26 août 200825 déc. 2008Nokia CorporationMethod and equipment for accessing a telecommunication network
US20090073913 *30 juin 200419 mars 2009Globespan Virata IncorporatedDirect link relay in a wireless network
US20090164643 *23 févr. 200925 juin 2009Cisco Technology, Inc.System and Method for Concurrently Utilizing Multiple System Identifiers
US20090187670 *19 juin 200823 juil. 2009Lg Electronics Inc.Method for suspending and resuming content transmission/reception
US20090265782 *18 sept. 200822 oct. 2009Hon Hai Precision Industry Co., Ltd.Mobile station and method for avoiding attacks
US20090270081 *7 juil. 200929 oct. 2009Ji-Hye LeeMethod for suspending and resuming content transmission/reception
US20090276646 *10 avr. 20095 nov. 2009Samsung Electronics Co., Ltd.Method and apparatus for data transmission in wireless local access network and system therefor
US20090296618 *8 août 20093 déc. 2009Research In Motion LimitedPower saving via variable listen intervals in a wlan
US20090312014 *8 oct. 200817 déc. 2009Hon Hai Precision Industry Co., Ltd.Mobile terminal device and roaming method thereof
US20090313359 *14 août 200917 déc. 2009Symantec CorporationAutomatic switching network points based on configuration profiles
US20100002623 *10 juil. 20097 janv. 2010Broadcom CorporationToken-Based Receiver Diversity
US20100049855 *27 oct. 200925 févr. 2010Cisco Technology, Inc.Distributed Network Communication System Which Selectively Provides Data to Different Network Destinations
US20100110991 *7 janv. 20106 mai 2010Interdigital Technology CorporationUser equipment for physical layer automatic repeat request
US20100128655 *29 janv. 201027 mai 2010Broadcom CorporationReconfiguration Of A Communication System
US20100128710 *8 déc. 200927 mai 2010Symbol Technologies, Inc.Infrastructure for wireless lans
US20100150093 *23 déc. 200917 juin 2010Wi-Lan, Inc.Methods and Systems for Transmission of Multiple Modulated Signals Over Wireless Networks
US20100177677 *1 déc. 200915 juil. 2010Broadcom CorporationDistributed MAC architecture for wireless repeater
US20100189013 *19 mars 201029 juil. 2010Broadcom CorporationPlug-In-Playable Wireless Communication System
US20100189041 *31 mars 201029 juil. 2010Broadcom CorporationUtilization of the internet protocol to facilitate communication involving mobile devices
US20100202428 *11 mars 201012 août 2010Cisco Technology, Inc.System and Method for Concurrently Utilizing Multiple System Identifiers
US20120033633 *13 oct. 20119 févr. 2012Wi-Lan, Inc.Method and system for adaptively obtaining bandwidth allocation requests
USRE4312727 juil. 200924 janv. 2012Intellectual Ventures I LlcEvent-based multichannel direct link
USRE4521217 janv. 201228 oct. 2014Intellectual Ventures I LlcEvent-based multichannel direct link
CN1653837B10 mars 20038 déc. 2010空气磁体公司Detecting a hidden node in a wireless local area network
CN100571460C26 août 200416 déc. 2009英特尔公司Secured roaming method and apparatus
CN101069173B20 avr. 200423 juin 2010国际商业机器公司Method for low power operation of wireless lan interfaces
DE102004040466B4 *20 août 200431 mars 2011Intel Corporation, Santa ClaraVerfahren und Vorrichtung zum sicheren Roamen
WO2001043467A1 *7 déc. 200014 juin 2001Proxim, Inc.Flexible wireless lan architecture based on a communication server
WO2003025597A1 *13 sept. 200227 mars 2003Networks Associates Technology, Inc.Decoding and detailed analysis of captured frames in an ieee 802.11 wireless lan
WO2003061313A1 *10 janv. 200324 juil. 2003Airflow NetworksMobility support via routing
WO2003079708A1 *10 mars 200325 sept. 2003Airmagnet, Inc.Detecting a hidden node in a wireless local area network
WO2004062308A2 *15 sept. 200322 juil. 2004Philips Semiconductors Dresden AgMethod for establishing a connection between a mobile station and a communication network
WO2004062308A3 *15 sept. 200318 nov. 2004Philips Semiconductors DresdenMethod for establishing a connection between a mobile station and a communication network
WO2004095193A3 *20 avr. 200414 juin 2007IbmSystem for low power operation of wireless lan interfaces
WO2005069806A3 *12 janv. 200526 oct. 2006Avaya Technology CorpEfficient power management in wireless local area networks
Classifications
Classification aux États-Unis370/338, 455/161.1
Classification internationaleH04L12/28, H04W36/02
Classification coopérativeH04W36/02
Classification européenneH04W36/02
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30 déc. 1996ASAssignment
Owner name: LUCENT TECHNOLOGIES, NEW JERSEY
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